The present invention relates to a system and method for displaying an object in space, in particular, the invention relates to a projection system for simulating an object suspended in a viewable volume of space.
There is an increasing demand for products which enhance the visual experience of the observer. One particular category of these products is appealing because of their ability to make an observer accept as true that which the observer intuitively knows is not possible. For example, in one instance, these products may be designed to simulate on object suspended in free-space. In fact, what the observer sees is a virtual image of the object.
U.S. Pat. No. 3,647,284 to Ellings et al., is an example of one such device found in the prior art which simulates a suspended object. The Ellings patent discloses using mirrors in its arrangement. In particular, Ellings discloses a pair of concave mirrors placed opposite one another. An object to be projected, such as a coin or piece of jewelry is placed on a concaved surface of one of the mirrors. A real image of the object is then projected through a small opening in the surface of the opposite mirror. In this way, the object is made to appear three-dimensional and suspended in free-space.
U.S. Pat. No. 4,776,118 to Mizuno is another prior art system utilizing a mirrored device to simulate an object suspended in free-space. The Mizuno arrangement uses a concave mirror positioned opposite a television monitor. The television monitor displays a two-dimensional flat image which is projected on a transparent surface above the Mizuno projection device.
The Ellings and Mizuno systems are typical of prior art projection devices which are used to project images in free space. However, these devices are relatively simplistic. In other variations, the prior art systems may be more complex. For example, some prior art projection systems may require lenses, prisms, projectors, additional mirrors or the like for image projection.
One such sophisticated prior art system is disclosed in U.S. Pat. No. 4,322,743 to Rickert. The Rickert system uses a projection optic to focus an image of an object on a special screen. In one embodiment, the screen is a concave screen such as on a projection T.V. The screen concentrates the light forming the image. The image is focused on the surface of the screen and is brightest at the radius of the screen at the angle of projection.
Thus, as can be seen the prior art provides numerous devices for projecting images simulating objects suspended in free space. However, the images produced by the prior art systems are typically not the most effective simulation of the object. One reason is that, in general, the prior art systems do not take into consideration the means by which the viewers eye/brain system processes visual images. A more effective image projection system should make use of the manner in which the eye/brain system processes three-dimensional objects. These processes or perceptual cues impress upon the observer that the image he sees is actually located where it appears to be.
One method for using visual or perceptual cues to enhance a viewers experience is disclosed in U.S. Pat. No. 5,886,818 to Summer et al., which proposes using perceptual cues embedded within a video data stream. The Summer invention is limited, however, in that it uses flat, two-dimensional perceptual cues, which are not a true representation of actual three-dimensional perceptual cues to which the eye/brain system responds. The two-dimensional cues described in Summer are inherently limited in their effectiveness.
Simulation of an object suspended in space is most effective where the viewer is made to think that the image he sees is cast in three-dimensions and at a specific location in space. Three-dimensional images are those that give the perception that a solid form exists where one does not. Effectively, the eye/brain system uses its experience with perceptual cues to correlate certain visual and environmental references to corroborate the existence of a three-dimensional object. To understand how the brain perceives three-dimensional objects and their physical locations, it must first be understood how perceptual cues work to create a credible visual image.
In brief, the human brain determines whether the image is real by relating the images to the actual environment. That is, the brain makes use of environmental references to perceive an object in three-dimensions. Perceptual cues are patterns, physical objects, and experiential data that the eye/brain recognizes which aid the eye in determining particular characteristics about the image being processed. They may include perceptions about the object""s size, position, and/or color relative to the environment in which the object is viewed.
Initially, an observer""s eyes settle on a fixation point representing the distance at which corresponding retinal points within the eye are stimulated. A horopter is an imaginary plane in space drawn through that fixation point. Images in an observer""s right and left eye received from objects near the horopter are fixed by the eye/brain system into single objects at the same depth plane. It is through the various properties of visual perception that environmental references relative to the horpoter, encourage a credible 3 dimensional impression in the mind.
For example, the property of visual perception known as optical occlusion focuses on the generally opaque nature of matter. In particular, through experience the human eye/brain system expects that where objects are in the same line of sight, objects nearer the observer will hide objects more distant from the observer. The eye/brain system will receive environmental visual cues such as which object is occluded relative to the other. The eye/brain system then determines that the occluded object is farther in distance from the observer than an object which in not occluded.
Another property of visual perception, which encourages three-dimensional impression on the eye/brain system, is stereopsis. Stereopsis makes use of the observer""s biocular vision. In real life, each eye gets a slightly different view of the world when pointed at the same object. This is called stereoptic viewing. Through stereoptic viewing the eye/brain system perceives objects from two different vantage points. The brain, therefore, receives information about the viewing depth of the object from the distinct vantage points by triangulating the depth information to calculate a measurable distance of the object from the observer. More particularly, when the brain tells both eyes to focus on object, if the object is, for example, within approximately 10 feet, the eyes triangulate on the objects position and converge on the object at the point of triangulation. The closer the object, the greater the angle of convergence.
In yet another property of visual perception by which environmental cues promote three-dimensional impression, the eye/brain system makes use of its visual, historical, experience to interpret object. In general, a typical observer develops certain conceptions of object size relative to the environment in which it is viewed. The eye/brain system compares objects of known size in order to estimate their relative locations. The brain, based on previous experience, compares the observed object to the known size of that object and/or objects in the surrounding environment. Aware of the differences between the known size and the observed size, the brain then calculates a viewing distance that corresponds to the differences in object size.
In still another property of visual perception promoting three-dimensional impression on the eye/brain system, an object in motion at different distances from an observer appears to move at different speeds. Thus, as an object in motion moves toward an observer, the object appears to be picking up speed although the object""s speed is constant. This motion parallax exists because the images of the approaching object moves at a greater distance on the retina in the same time than the images of the objects that are farther away.
Still another visual property promoting three-dimensional perception involves shadowing and lighting. For example, the eye/brain system is conditioned to recognize that light striking a three-dimensional surface produces shadows and highlights either on the surface itself or and/or adjacent surfaces upon which shadows are cast. The eye/brain system recognizes that two dimensional surfaces do not produce shadows as produced by a three-dimensional image. Consequently, where an image appears to include or cast shadows, the eye/brain system interprets that image as three-dimensional.
As noted, the visual perception properties are those by which three-dimensional imagery is promoted to the observer. Thus, to give a true image of an object, a device which purpose is to provide an observable three-dimensional image of an object must by its construction and operation take into consideration the visual perception properties discussed herein. The greater the number of visual perception properties taken into consideration, the more favorable and credible an observer""s viewing experience.
The effect of the above visual perception properties on the eye/brain system is significantly enhanced by focal accommodation. Focal accommodation is the property of the eye/brain system which forces the eyes to focus on objects within about 10 feet from the observer as a beginning reference point. That is, within about 10 feet, the eyes will instinctively look for environmental cues which corroborate what the brain perceives. Contrarily, where the object is at a greater distance from the observer, the eyes will focus on optical infinity, with no particular focal point upon which to cue.
Presently, no known projection device is designed to focus an observer""s eye/brain system by incorporating a plurality of visual perception cues. Therefore, a need exists for a real image projection system that makes use of the manner in which eye/brain system processes images to enhance the quality of the image. Such a system is highly desirable in that the observer will more readily believe the existence of the floating object and thus have a more credible viewing experience.
The above limitations and other problems of the prior art are overcome in accordance with the present invention. The present invention creates real images in such a manner as to create convergence of the eyes by using the natural operation of the eye/brain system. The invention makes use of environmental perceptual cues to encourage the brain to perceive an image in 3 dimensions (three-dimensional) and at a specific location in space. The environmental cues employed by the present invention promote a three-dimensional image on an observer""s eye/brain system through the visual perception properties.
In accordance with one embodiment of the invention, a real image projection system is provided in which an object is presented to the reflective surface of an optical assembly. The optical assembly may then project a real image of the object between the observer and the optical assembly reflective surface. The real image system may additionally employ one or more concave or flat mirrors for image projection. Further, the optical assembly may be contained within a housing including an aperture. The housing may be thematic, personalized or generic. The aperture which defines a viewable volume of space into which the real image is projected may be such that it promotes three-dimensional impression upon the observer. The optical assembly and/or housing may be provided a device positioning apparatus for orienting the housing or assembly to position the image for the observer.
In accordance with exemplary embodiments of the invention, the object for projection may be static or dynamic. Where the object is dynamic, the object may be presented using any apparatus for moving or animating the object. In one exemplary embodiment the apparatus may alter the position of the object relative to the reflective surface. The apparatus may move the object from a distance remote from the optical assembly to near the optical assembly focal point. In this way, the image of the object may be made to appear to move toward the observer. In another embodiment, the apparatus may move only a portion or sub-portion of the object. So, for example, where the object resembles a human form, the apparatus may animate one or more of the objects limbs, sub-parts (mouth, nose, eyes, etc.) or the like. Further, the optical assembly and/or housing may include a device or apparatus for positioning the assembly or housing. Such apparatus may move the assembly or housing horizontally, vertically, spatially, or the like.
In yet another embodiment of the invention, the real image projection system may include environmental cues designed to focus the observers eye/brain system. The visual cues may be static or dynamic, and may include physical objects, lights or shadows. The visual cues may be included on the projection system housing for encouraging the observer""s eye/brain system to focus in on the aspects of the image to effectively promote three-dimensional perception. In one embodiment, the various cues may be part of the housing, remote from the housing, or the housing itself.
In still another embodiment of the invention, the real image projection system may employ sound generating devices for further encouraging three-dimensional perception. The sound generating devices may present audible noises, music, or the like which may be designed to match the overall theme of the projection system.